1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/*
* Copyright (c) 2015-2017, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/** \file
* \brief Region analysis and utility functions.
*/
#ifndef NG_REGION_H
#define NG_REGION_H
#include "ng_holder.h"
#include "util/container.h"
#include "util/graph_range.h"
#include <unordered_map>
#include <vector>
namespace ue2 {
/** \brief Assign a region ID to every vertex in the graph. */
std::unordered_map<NFAVertex, u32> assignRegions(const NGHolder &g);
/** \brief True if vertices \p a and \p b are in the same region. */
template <class Graph>
bool inSameRegion(const Graph &g, NFAVertex a, NFAVertex b,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
assert(contains(region_map, a) && contains(region_map, b));
return region_map.at(a) == region_map.at(b) &&
is_special(a, g) == is_special(b, g);
}
/** \brief True if vertex \p b is in a later region than vertex \p a. */
template <class Graph>
bool inLaterRegion(const Graph &g, NFAVertex a, NFAVertex b,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
assert(contains(region_map, a) && contains(region_map, b));
u32 aa = g[a].index;
u32 bb = g[b].index;
if (bb == NODE_START || bb == NODE_START_DOTSTAR) {
return false;
}
if (aa == NODE_START || aa == NODE_START_DOTSTAR) {
return true;
}
if (bb == NODE_ACCEPT || bb == NODE_ACCEPT_EOD) {
return true;
}
if (aa == NODE_ACCEPT || aa == NODE_ACCEPT_EOD) {
return false;
}
return region_map.at(a) < region_map.at(b);
}
/** \brief True if vertex \p b is in an earlier region than vertex \p a. */
template <class Graph>
bool inEarlierRegion(const Graph &g, NFAVertex a, NFAVertex b,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
assert(contains(region_map, a) && contains(region_map, b));
u32 aa = g[a].index;
u32 bb = g[b].index;
if (bb == NODE_START || bb == NODE_START_DOTSTAR) {
return true;
}
if (aa == NODE_START || aa == NODE_START_DOTSTAR) {
return false;
}
if (bb == NODE_ACCEPT || bb == NODE_ACCEPT_EOD) {
return false;
}
if (aa == NODE_ACCEPT || aa == NODE_ACCEPT_EOD) {
return true;
}
return region_map.at(b) < region_map.at(a);
}
/** \brief True if vertex \p v is an entry vertex for its region. */
template <class Graph>
bool isRegionEntry(const Graph &g, NFAVertex v,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
// Note that some graph types do not have inv_adjacent_vertices, so we must
// use in_edges here.
for (const auto &e : in_edges_range(v, g)) {
if (!inSameRegion(g, v, source(e, g), region_map)) {
return true;
}
}
return false;
}
/** \brief True if vertex \p v is an exit vertex for its region. */
template <class Graph>
bool isRegionExit(const Graph &g, NFAVertex v,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
for (auto w : adjacent_vertices_range(v, g)) {
if (!inSameRegion(g, v, w, region_map)) {
return true;
}
}
return false;
}
/** \brief True if vertex \p v is in a region all on its own. */
template <class Graph>
bool isSingletonRegion(const Graph &g, NFAVertex v,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
for (const auto &e : in_edges_range(v, g)) {
auto u = source(e, g);
if (u != v && inSameRegion(g, v, u, region_map)) {
return false;
}
for (auto w : ue2::adjacent_vertices_range(u, g)) {
if (w != v && inSameRegion(g, v, w, region_map)) {
return false;
}
}
}
for (auto w : adjacent_vertices_range(v, g)) {
if (w != v && inSameRegion(g, v, w, region_map)) {
return false;
}
for (const auto &e : in_edges_range(w, g)) {
auto u = source(e, g);
if (u != v && inSameRegion(g, v, u, region_map)) {
return false;
}
}
return true;
}
return true;
}
/**
* \brief True if the region containing vertex \p v is optional. The vertex \p v
* should be a region leader.
*/
template <class Graph>
bool isOptionalRegion(const Graph &g, NFAVertex v,
const std::unordered_map<NFAVertex, u32> ®ion_map) {
assert(isRegionEntry(g, v, region_map));
DEBUG_PRINTF("check if r%u is optional (inspecting v%zu)\n",
region_map.at(v), g[v].index);
// Region zero is never optional.
assert(contains(region_map, v));
if (region_map.at(v) == 0) {
return false;
}
// Optional if v has a predecessor in an earlier region that has a
// successor in a later one.
for (const auto &e : in_edges_range(v, g)) {
auto u = source(e, g);
if (inSameRegion(g, v, u, region_map)) {
continue;
}
DEBUG_PRINTF(" searching from u=%zu\n", g[u].index);
assert(inEarlierRegion(g, v, u, region_map));
for (auto w : adjacent_vertices_range(u, g)) {
DEBUG_PRINTF(" searching to w=%zu\n", g[w].index);
if (inLaterRegion(g, v, w, region_map)) {
return true;
}
}
return false;
}
return false;
}
} // namespace ue2
#endif
|
